Navigation systems are available that provide end users with various navigation-related functions and features. For example, some navigation systems are able to determine an optimum route to travel along a road and/or a pedestrian pathway from an origin location to a destination location in a geographic region. Using input from the end user, and optionally from equipment that can determine the end user's location (such as a GPS system), the navigation system can examine various potential routes between the origin and destination locations to determine the optimum route.
The navigation system may then provide the end user with information about the optimum route in the form of guidance that identifies the driving and/or walking maneuvers required to be taken by the end user to travel from the origin to the destination location. The guidance may take the form of visual and/or audio instructions that are provided along the way as the end user is traveling the route. Some navigation systems are able to show detailed maps on displays outlining the route, the types of maneuvers to be taken at various locations along the route, locations of certain types of features, and so on.
In order to provide these and other navigation-related functions and features, navigation systems use geographic data. The geographic data may be in the form of one or more geographic databases that include data representing physical features in the geographic region. The geographic database includes information about the represented geographic features, such as the positions of the roads, speed limits along portions of roads, address ranges along the road portions, turn restrictions at intersections of roads, direction restrictions, such as one-way streets, and so on. Additionally, the geographical database may include information about pedestrian pathways, such as whether the pathway is paved or unpaved, whether the pathway is wheel chair accessible, and is whether crosswalks exist. The geographic data may also include information about points of interest, such as restaurants, hotels, airports, gas stations, stadiums, police stations, and so on.
While navigation systems provide useful information to users, there continues to be room for new features and improvements. One area in which there is room for improvement relates to crosswalks. A pedestrian crossing or crosswalk is a designated point on a road at which some means are employed to assist pedestrians wishing to cross. Crosswalks are designed to keep pedestrians together where they can be seen by motorists as they cross the flow of vehicular traffic. Crosswalks are often at intersections, but may also be at other points on busy roads that would otherwise be difficult to attempt to cross. Crosswalks are also common near schools or in other areas where there are a large number of children.
One method of representing a crosswalk using geographic data is described in U.S. Pat. No. 6,374,182, which is assigned to the same assignee as the subject application. In U.S. Pat. No. 6,374,182, crosswalk information may be included as an attribute of a road segment data entity and/or a node data entity. The crosswalk information associated with a road segment data entity may include crosswalk location data that indicates the locations along the length of a represented road segment at which a pedestrian crosswalk exists. The crosswalk location data associated with a node data entity may include data that indicates which of the road segments meet at the location represented by the node data that have pedestrian crosswalks.
Although the crosswalk representation described in U.S. Pat. No. 6,374,182 is useful, there exists room for improvement. Accordingly, it would be beneficial to represent a pedestrian crosswalk based on data that represents corners of an intersection.